Farmers typically employ agricultural fertilizers to maintain good yields, product quality and profitability. Organic farmers, like any other, need to provide nitrogen to their crops, but also must adhere to strict requirements to ensure that the nitrogen source is approved for use in organic crop farming. In addition, determining which organic fertilizer material to use, how much to apply and when to apply it, is vital, and is even considered more challenging organically than it is conventionally. One major challenge when using organic nitrogen as a fertilizer is synchronizing the timing of mineralization with plant demand as nitrogen mineralization into ammonium and nitrate forms is required before uptake by most plants. Failure to synchronize nitrogen mineralization with crop uptake can lead to plant nutrient deficiencies, excessive soil nitrogen beyond the growing season, and the potential for excessive nitrate leaching.
Manures and composts, which are commonly used as nitrogen sources in organic farming, contain and release nitrogen slowly and in varying amounts. As such, it is difficult to use them efficiently for optimal crop growth. In addition, as compost ages, the availability of the nitrogen it contains tends to decrease. An animal-based organic nitrogen fertilizer, like blood meal, may “burn” delicate vegetable roots if applied without mixing into the soil, or too close to established plants. In addition to burning roots, animal-based fertilizers may also attract rats, raccoons, opossums, and other unwelcome nocturnal pests.